ID   RDRP_BPSP               Reviewed;         576 AA.
AC   P09675;
DT   01-JUL-1989, integrated into UniProtKB/Swiss-Prot.
DT   01-JUL-1989, sequence version 1.
DT   03-AUG-2022, entry version 72.
DE   RecName: Full=RNA-directed RNA polymerase subunit beta;
DE            EC=2.7.7.48 {ECO:0000250|UniProtKB:P14647};
DE   AltName: Full=RNA replicase beta chain;
OS   Enterobacteria phage SP (Bacteriophage SP).
OC   Viruses; Riboviria; Orthornavirae; Lenarviricota; Leviviricetes;
OC   Levivirales; Leviviridae; Allolevivirus.
OX   NCBI_TaxID=12027;
OH   NCBI_TaxID=562; Escherichia coli.
RN   [1]
RP   NUCLEOTIDE SEQUENCE [MRNA].
RX   PubMed=3399390; DOI=10.1093/nar/16.13.6205;
RA   Hirashima A., Hirose T., Inayama S., Inokuchi Y., Jacobson A.B.;
RT   "Analysis of the complete nucleotide sequence of the group IV RNA coliphage
RT   SP.";
RL   Nucleic Acids Res. 16:6205-6221(1988).
CC   -!- FUNCTION: This is the catalytic subunit of the viral RNA-dependent RNA
CC       polymerase complex. This complex is involved in viral RNA replication
CC       that produces (+)-stranded genomes via a complementary, (-)-stranded
CC       intermediate. Binds RNA cooperatively with the host ribosomal protein
CC       S1. {ECO:0000250|UniProtKB:P14647}.
CC   -!- CATALYTIC ACTIVITY:
CC       Reaction=a ribonucleoside 5'-triphosphate + RNA(n) = diphosphate +
CC         RNA(n+1); Xref=Rhea:RHEA:21248, Rhea:RHEA-COMP:14527, Rhea:RHEA-
CC         COMP:17342, ChEBI:CHEBI:33019, ChEBI:CHEBI:61557, ChEBI:CHEBI:140395;
CC         EC=2.7.7.48; Evidence={ECO:0000250|UniProtKB:P14647,
CC         ECO:0000255|PROSITE-ProRule:PRU00539};
CC   -!- COFACTOR:
CC       Name=Mg(2+); Xref=ChEBI:CHEBI:18420;
CC         Evidence={ECO:0000250|UniProtKB:P14647};
CC       Note=Binds 2 Mg(2+) per subunit, Ca(2+) is used in crystallization to
CC       prevent RNA polymerase activity. {ECO:0000250|UniProtKB:P14647};
CC   -!- SUBUNIT: Homodimer; the replicase complex can dimerize. Part of the
CC       viral RNA-dependent RNA polymerase complex, the other subunits are the
CC       host ribosomal protein S1, EF-Tu and EF-Ts. S1 is needed for the
CC       initiation of genomic RNA (+)-strand replication.
CC       {ECO:0000250|UniProtKB:P14647}.
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DR   EMBL; X07489; CAA30375.1; -; mRNA.
DR   PIR; S01965; S01965.
DR   SMR; P09675; -.
DR   PRIDE; P09675; -.
DR   Proteomes; UP000000728; Genome.
DR   GO; GO:0046872; F:metal ion binding; IEA:UniProtKB-KW.
DR   GO; GO:0000166; F:nucleotide binding; IEA:UniProtKB-KW.
DR   GO; GO:0003723; F:RNA binding; IEA:UniProtKB-KW.
DR   GO; GO:0003968; F:RNA-directed 5'-3' RNA polymerase activity; IEA:UniProtKB-KW.
DR   GO; GO:0039694; P:viral RNA genome replication; IEA:InterPro.
DR   InterPro; IPR043502; DNA/RNA_pol_sf.
DR   InterPro; IPR007096; RNA-dir_Rpol_phage_catalytic.
DR   InterPro; IPR005093; RNArep_beta.
DR   Pfam; PF03431; RNA_replicase_B; 1.
DR   SUPFAM; SSF56672; SSF56672; 1.
DR   PROSITE; PS50522; RDRP_PHAGE; 1.
PE   2: Evidence at transcript level;
KW   Magnesium; Metal-binding; Nucleotide-binding; Nucleotidyltransferase;
KW   Reference proteome; RNA-binding; RNA-directed RNA polymerase; Transferase;
KW   Viral RNA replication.
FT   CHAIN           1..576
FT                   /note="RNA-directed RNA polymerase subunit beta"
FT                   /id="PRO_0000164856"
FT   DOMAIN          259..391
FT                   /note="RdRp catalytic"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU00539"
FT   BINDING         274
FT                   /ligand="Mg(2+)"
FT                   /ligand_id="ChEBI:CHEBI:18420"
FT                   /ligand_label="1"
FT                   /evidence="ECO:0000250|UniProtKB:P14647"
FT   BINDING         274
FT                   /ligand="Mg(2+)"
FT                   /ligand_id="ChEBI:CHEBI:18420"
FT                   /ligand_label="2"
FT                   /evidence="ECO:0000250|UniProtKB:P14647"
FT   BINDING         359
FT                   /ligand="Mg(2+)"
FT                   /ligand_id="ChEBI:CHEBI:18420"
FT                   /ligand_label="1"
FT                   /evidence="ECO:0000250|UniProtKB:P14647"
FT   BINDING         359
FT                   /ligand="Mg(2+)"
FT                   /ligand_id="ChEBI:CHEBI:18420"
FT                   /ligand_label="2"
FT                   /evidence="ECO:0000250|UniProtKB:P14647"
FT   BINDING         360
FT                   /ligand="Mg(2+)"
FT                   /ligand_id="ChEBI:CHEBI:18420"
FT                   /ligand_label="1"
FT                   /evidence="ECO:0000250|UniProtKB:P14647"
FT   BINDING         360
FT                   /ligand="Mg(2+)"
FT                   /ligand_id="ChEBI:CHEBI:18420"
FT                   /ligand_label="2"
FT                   /evidence="ECO:0000250|UniProtKB:P14647"
SQ   SEQUENCE   576 AA;  65398 MW;  EAB30613C21C5F6C CRC64;
     MPKTASRRRE ITQLLGKVDI NFEDDIHMSI ANDLFEAYGI PKLDSAEECI NTAFPSLDQG
     VDTFRVEYLR AEILSKFDGH PLGIDTEAAA WEKFLAAEEG CRQTNERLSL VKYHDNSILS
     WGERVIHTAR RKILKLIGES VPFGDVALRC RFSGGATTSV NRLHGHPSWK HACPQDVTKR
     AFKYLQAFKR ACGDVVDLRV NEVRTSNKAV TVPKNSKTDR CIAIEPGWNM FFQLGVGAVL
     RDRLRLWKID LNDQSTNQRL ARDGSLLNHL ATIDLSAASD SISLKLVELL MPPEWYDLLT
     DLRSDEGILP DGRVVTYEKI SSMGNGYTFE LESLIFAAIA RSVCELLEID QSTVSVYGDD
     IIIDTRAAAP LMDVFEYVGF TPNRKKTFCD GPFRESCGKH WFQGVDVTPF YIRRPIRCLA
     DMILVLNSIY RWGTVDGIWD PRALTVYEKY LKLLPRNWRR NRIPDGYGDG ALVGLATTNP
     FVIVKNYSRL YPVLVEVQRD VKRSEEGSYL YALLRDRETR YSPFLRDADR TGFDEAPLAT
     SLRRKTGRYK VAWIQDSAFI RPPYLITGIP EVKLAS